8 week for screed to dry before SLC? Is this true?

[markyyyyyy]

I have a sloping kitchen floor and i have used screed to level the floor. The deepest part of the screed is 7.5cm deep.

Mapei technical said that i have to wait 8 weeks before i can apply mapei 3240 self levelling compound. Is this really true?

I'm half way through a kitchen project and my house is freezing as i had to chop the bottom of the door off to get the floor levelled. If it is true than i will obviously wait out.

just wondering what builders usually do? What is the issue with laying SLC on top of the screed before 8 weeks?

 

[Notch7]

yes it is true -screed dries at the rate of 1mm a day, or half that if its thick

builders usually fudge it "oh its been down 3 1/2 weeks it looks dry, lets get the tiling done"

I used to use Mapei top cem -dry in 24 hours


you may not have to wait 8 weeks in a heated property, but just accept it will continue to dry out and there is a small risk of that damp coming through the SLC and delaminating it.

 

[HERTS P&D]

Mine is 90mm and I was told to wait 6 weeks.

Andy

 

[markyyyyyy]

yes it is true -screed dries at the rate of 1mm a day, or half that if its thick

builders usually fudge it "oh its been down 3 1/2 weeks it looks dry, lets get the tiling done"

I used to use Mapei top cem -dry in 24 hours


you may not have to wait 8 weeks in a heated property, but just accept it will continue to dry out and there is a small risk of that damp coming through the SLC and delaminating it.

cheers. Yes i'll wait. is it worth getting a dehumidifier on in the room? It's been drying or 3 weeks now, and there has been no radiator in the room as i've gutted the whole lot

 

[catlad]

I'm confused why if you have screeded the floor do you need to use self leveller?
Are you tiling the floor?

 

[^woody^]

The drying rate is based on new build, unheated areas with some ventilation and other construction moisture already in the structure. In a dry heated home where temperature and ventilation can be controlled, the time can be drastically reduced.

Yes a dehumidifier can help but the more industrial types are better than a £15 jobbie for Argos. But you are better off with some heat, a fan and an open window and closed doors and this will dry it off sufficient for coating within one-two weeks.

 

[markyyyyyy]

I'm confused why if you have screeded the floor do you need to use self leveller?
Are you tiling the floor?

2 reasons

1. I am a diyer hence not a perfectly level finish
2. I couldn't screed any less depth of 25mm so need to self level that and the self level the lot